Senior Python Engineer in London

Join to apply for the Senior Python Engineer role at Cleo. At Cleo, we're not just building another fintech app. We're embarking on a mission to fundamentally change humanity's relationship with money. Imagine a world where everyone, regardless of background or income, has access to a hyper‐intelligent financial advisor in their pocket. That's the future we're creating.

Cleo is a rare success story: a profitable, fast‐growing unicorn with over $200 million in ARR and growing over 2x year‐over‐year. This isn't just a job; it's a chance to join a team of brilliant, driven individuals who are passionate about making a real difference. We have an exceptionally high bar for talent, seeking individuals who are not only at the top of their field but also embody our culture of collaboration and positive impact.

We are looking for a Senior Python Engineer to join our Platform engineering team at Cleo. The right candidate will support our product teams in achieving their OKRs while championing best practices in python engineering and MLOps. In this role, you'll work directly with product teams to ensure they effectively adopt the tools, frameworks, and processes provided by the Data Platform team, enabling them to build scalable, efficient, and reliable data and ML solutions. You'll help teams implement and operate robust python services, monitoring strategies, and cost‐efficient practices to improve their data‐driven capabilities.

At the same time, you'll act as a crucial bridge between product teams and the Data Platform team, gathering insights on real‐world challenges, gaps, and pain points in the existing platform. By surfacing these issues and collaborating with the platform team, you'll contribute to the continuous improvement of our internal tooling and infrastructure, ensuring it better serves the needs of our engineers and data scientists. This is an opportunity to blend hands‐on engineering with strategic impact, influencing both product success and the evolution of our data platform.

What do you need?

• Software engineering and best practices – proficiency in Python, code quality and maintainability
• Containerisation & orchestration – Docker, Kubernetes
• Understanding value and product thinking
• Experience working cross‐functionally – Ability to work with data scientists, software engineers, and product managers to align ML initiatives with business goals
• Experience deploying and operating APIs – moving more into the ability to deploy/operate microservices
• Strong knowledge of streaming PySpark
• Experience building and managing data pipelines e.g. Kubeflow, MLflow, Airflow or Flyte
• In‐depth knowledge of Python 3.x, standard libraries, and core language features
• Familiarity with Django, Flask, FastAPI
• Data handling – Pydantic, Pandas, SQLAlchemy
• Async programming – asyncio, concurrent.futures

What do you get for all your hard work?

• Company‐wide performance reviews every 6 months
• Generous pay increases for high‐performing team members
• Equity top‐ups for team members getting promoted
• 25 days annual leave a year + public holidays (+ an additional day for every year you spend at Cleo, up to 30 days)
• 6% employer‐matched pension in the UK
• Private Medical Insurance via Vitality, dental cover, and life assurance
• Enhanced parental leave
• 1 month paid sabbatical after 4 years at Cleo
• Regular socials
• We'll pay for your OpenAI subscription
• Online mental health support via Spill
• Workplace Nursery Scheme

We strongly encourage applications from people of colour, the LGBTQ+ community, people with disabilities, neurodivergent people, parents, carers, and people from lower socio‐economic backgrounds. If there's anything we can do to accommodate your specific situation, please let us know.